Wildcards are used to represent one or more unknown characters in a word. They are useful for searching for all documents containing variations of a word or when you are not sure of the exact characters contained in a word.
| Wildcard | Description |
|---|---|
| * | (Asterisk) Represents zero or more missing characters. For example, govern*s would find "governors," "governments," and "governs." |
| ? | (Question mark) Represents any single character. For example, gr?y would find "gray" and "grey," but not "gravy." |
| [] | (Brackets) Brackets are also used as a wildcard for any single character. A limited set of replacement characters can be specified within the brackets. For example, gr[ae]y would find "gray" and "grey," but no others. |
| - | (Dash) Indicates a range of characters. For example, b[a-i]tter would find the words "batter," "better" and "bitter," but not "butter." |
| [0-9] | Represents any single digit number. For example, [0-9][0-9] would find any two-digit number (but not a one- or three-digit number), and [0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9][0-9][0-9] would find a social security number. |
Wildcards may be combined. For example, br[a-o]ke* would find all of the following words: brake, braked, broke, broker, and broken.
Performance
Searches that use strings starting with a wildcard (e.g. *term) are significantly slower than searches that use strings ending with a wildcard (e.g. term*).